1. Field of the Invention
The present invention relates to a flat panel display, and more particularly, to a flat panel display using a micro-electromechanical device for blocking or passing light.
2. Description of the Related Art
FIG. 1 is a cross-sectional view showing a conventional color liquid crystal display.
As shown in FIG. 1, formed at a lower portion of a back glass substrate 2 are a light diffusing plate (not shown) and a polarizing plate 1, and at an upper portion of the back glass substrate 2, there are formed an ITO transparent electrode 3 and an alignment film 4. The light diffusion plate transmits light from a backlight forming a uniform plane light from a fluorescent lamp. In addition, the ITO transparent electrode 3 is a transparent electric conductor, and the alignment film 4 is formed of a thin organic film made of polyimide in order to align liquid crystal molecules. At an upper portion of a front glass substrate 9, there is formed a polarizing plate 10, and at a lower portion of the front glass substrate 9, there are formed a color filter layer 8 arranged in the form of a mosaic, an ITO transparent electrode 7 and an alignment film 6. The color filter layer 8 is made of a resin film containing a dye or paint in three primary colors (red, green, blue). A liquid crystal layer 5 is injected between the back glass substrate 2 and the front glass substrate 9 and is supported by a sealant 11 and a support beam 12. The liquid crystal layer 5 is formed of a twisted-nematic liquid crystal material. The sealant 11 is positioned at an edge of a panel so as to serve as an adhesive for fixing the back glass substrate 2 and the front glass substrate 9. The support beam 12 supports the back glass substrate 2 and the front glass substrate 9.
In an optical switch device using the liquid crystal, as a conventional typical display device, a contrast change of light is excessively changed according to a viewing angle, and it is difficult to display moving images, since the liquid crystal needs a long period of reaction time. Further, there are some problems that the optical switch device exhibits low efficiency in utilizing the light and also needs a separate assembling process to inject and align the liquid crystal, thereby increasing a fabricating cost.
In a conventional mechanical optical shutter, generally, its power consumption is too high, and it is difficult to achieve its rapid operation and restrict its size to several hundred micro meter (xcexcm). Further, it is also impossible to provide a plurality of the optical shutters used as pixels for displaying an image.
Accordingly, it is an object of the present invention to provide a flat panel display, which has a high optical switching efficiency and a low fabricating cost, using a micro-electromechanical device as the optical switch device.
According to a first aspect of the present invention, a flat panel display using an micro-electromechanical device comprises a back glass substrate having a first transparent electrode of a transparent electric conductor; a front glass substrate having a color filter layer and a second transparent electrode; an micro-electromechanical device formed at the first transparent electrode to switch light; and a support beam for supporting the back glass substrate and the front glass substrate.
According to a second aspect of the present invention, a flat panel display using a micro-electromechanical device comprises a back glass substrate having a transparent electrode of a transparent electric conductor; a front glass substrate having a color filter layer; an micro-electromechanical device formed at the transparent electrode to switch light; and a support beam for supporting the back glass substrate and the front glass substrate.
According to a third aspect of the present invention, the micro-electromechanical device used in the flat panel display comprises a rotatory shifter rotatably moved by an electrostatic force due to a voltage difference between a shifting electrode and the transparent electrode vertically spaced from the shifting electrode, a mask and a window formed at the rotary shifter, and a support post for supporting the rotatory shifter.
According to a fourth aspect of the present invention, the support post used in the flat panel display is formed to sufficiently support the rotatory shifter, while the rotatory shifter is smoothly rotated.
According to a fifth aspect of the present invention, the mask and the window used in the flat panel display to block light or allow the light to pass therethrough.
According to a sixth aspect of the present invention, the micro-electromechanical device used in the flat panel display is formed in a double wing shape or a single wing shape.
According to a seventh aspect of the present invention, the micro-electromechanical device used in the flat panel display is a reflecting type structure without the window.
According to an eighth aspect of the present invention, the rotatory shifter used in the flat panel display is a structure having 2 to 10 stages.
According to a ninth aspect of the present invention, the micro-electromechanical device used in the flat panel display comprises a lower support post for supporting the horizontal shifter, an upper electrode for helping the optical switching operation, an upper support post for supporting the upper electrode, and a mask and a window formed at the horizontal shifter and the upper electrode.
According to a tenth aspect of the present invention, the horizontal shifter used in the flat panel display is translationally moved by a voltage difference between a voltage applied to the upper electrode and the transparent electrode and a voltage applied to the horizontal shifter.
Recently, a semiconductor processing technology for fabricating a mechanical structure having a size of a few micro meter (xcexcm) to several hundred micron meter (xcexcm), i.e. micro-machining technology is applied to a fabrication field of a sensor and an actuator having a size of a micron unit. In the present invention, the micro-machining technology is applied to a fabrication of the micro-electromechanical device used as an optical switch device, and the micro-electromechanical device is used for the display using the liquid crystal. Therefore, the display of the present invention has a high efficiency in utilizing the light. Since the precise semiconductor processing technology having a high productivity fabricates the micro-electromechanical device, the fabricating cost is remarkably reduced, and the pixel size of the display is more reduced.